Surgical drape and suction head for wound treatment

ABSTRACT

A wound therapy combination comprising a suction head and a surgical drape. The suction head comprises a planar flange portion and a tubular connector piece on a first face that communicates with an aperture extending to a second face. The second face is formed with projections that define flow channels for facilitating flow of liquids to the aperture.

RELATED APPLICATIONS

[0001] This application is a continuation of copending U.S. applicationSer. No. 09/835,500, which is a continuation of U.S. Ser. No.09/350,581, filed on Jul. 9, 1999, now U.S. Pat. No. 6,345,623, which isa continuation, under 35 U.S.C. §120 of PCT international applicationnumber PCT/GB98/02713 filed Sep. 9, 1998 and designating the UnitedStates, which claims priority to Great Britain patent application No.9719520.0 filed Sep. 12, 1997. By this reference, the full disclosure ofU.S. application Ser. No. 09/350,581, PCT international application No.PCT/GB98/02713, and Great Britain patent application No. 9719520.0 areincorporated herein as though fully set forth in their respectiveentirety.

FIELD OF THE INVENTION

[0002] This invention relates to surgical drapes and suction heads forwound treatment.

BACKGROUND OF THE INVENTION

[0003] Surgical drapes are widely used in surgical operations for thepurpose of reducing infection and facilitating the handling of skinaround incisions. Normally, they are transparent or translucent.Typically, they consist of a flexible, plastic film which isadhesive-coated and which is applied to the area of the operation, priorto making the incision. Surgical drapes are also used for attachingtreatment devices to patients after an operation, such as catheters ordrainage tubes.

[0004] A further, recently developed use is for connecting a suctiontube to a wound for the purpose of stimulating healing of the wound.Such use is described in our earlier applications Nos. WO 96/05873 andWO 97/18007.

[0005] Various proposals have been made in the past to design thesurgical drape so that handling of the sticky, flexible, plastic film isfacilitated. For example, U.S. Pat. No. 5,437,622 describes a surgicaldrape which is a laminate of three materials. The first materialcomprises a transparent, thin plastic film which is adhesive-coated andthe adhesive face protected with a layer of release-coated paper. Theother face of the adhesive-coated film is strengthened with areinforcing layer of a less flexible, plastic film. Handling bars orstrips are attached to the flexible, plastic film at its lateral edge tofacilitate handling of the flexible, plastic film after stripping awaythe protective releasable layer.

[0006] Where is it is desirable to use a surgical drape primarily toattach a device such a s a catheter to a wound area after an operationor for long term treatment, it is inconvenient for the surgeon or nurseto have to adapt a standard surgical drape for this purpose. It would bemore convenient to have a surgical drape which was suitable withoutadaptation to accommodate the treatment device.

SUMMARY OF THE INVENTION

[0007] One aspect of the present invention is directed to a solution tothis problem. A second aspect provides a combined surgical drape andsuction head for applying suction to a wound area to facilitateapplication of negative pressure therapy.

[0008] According to one aspect of the present invention there isprovided a surgical drape which comprises a thin, flexible,adhesive-coated plastic film and a strengthening layer applied to theface opposite to the adhesive coating, the strengthening layer being aplastic film which is thicker or less flexible than said adhesive-coatedfilm, and a protective, releasable layer applied to the adhesivecoating, the drape having an aperture through at least the strengtheningand adhesive coated film to permit, in use, access to a wound area, afirst edge of the drape having non-adhesive coated handling bars forseparating the adhesive-coated film from the protective layer, andwherein the protective layer comprises a separate strip extendingparallel to the first edge of the drape, and which protects the adhesivecoating in the region of the aperture and carries a flap overlapping theadjacent portion of the protective layer, said flap constituting ahandle for facilitating removal of said strip prior to use. Preferably,non-adhesive coated handling bars are positioned at opposite lateraledges of the drape.

[0009] In practice, surgical drapes may be manufactured by laminating anadhesive-coated flexible film, such as a polyurethane film, to aprotective releasable layer, such as a siliconized paper. Astrengthening layer of thicker plastic material, e.g. a polyolefin sucha polyethylene, may be applied to the non-adhesive coated face of theflexible film, so that a three-layer laminate is produced. Theselaminates are produced in substantial width and may be slitlongitudinally to the desired width and then laterally to form drapes ofthe desired size.

[0010] After slitting to a desired width, handling bars are normallyapplied to the adhesive-coated layers at one or both lateral edges tofacilitate separation of the film from the protective, releasable layer.While an aperture could be cut at the desired position through thelayers to accommodate a catheter or a device such as those described inour above-mentioned applications, it is difficult to handle the highlypliable and adhesive film after the releasable layer has been strippedoff.

[0011] Although the strengthening layer does somewhat improve thehandling characteristics, this is not a complete answer to the problem.However, the handling characteristics are substantially improved byproviding a protective layer which is in at least two portions, one ofwhich is in the form of a strip, e.g. one extending parallel to thelateral edges of the drape, and covering the peripheral area around theaperture through the drape. By providing a flap on this portion of thereleasable layer, it can be stripped off initially so that the drape isfirst positioned around the device which is to pass through theaperture, and then the remaining part of the protective releasable layeris stripped off to adhere the drape to the patient's skin around thearea to be treated.

[0012] In a preferred form of the invention in which negative pressuretherapy is applied to a wound area, the surgical drape described aboveis combined with a suction head having a connector piece which isadapted to be connected to a suction tube. Thus, in this embodiment, thesuction head can be adhered to the patient's skin in the area of thewound after removing the strip of protective releasable layer, and thenthe remaining part of the drape affixed to the patient's skin. In thisway, the suction head is held firmly in place and, at the same time,seals the suction head to the wound area and prevents leakage of airfrom atmosphere into the wound area.

[0013] The invention also includes a suction head having a design whichfacilitates the suction of fluid from a wound area.

[0014] According to a further feature of the invention, therefore, thereis provided a suction head for applying suction to a wound area whichcomprises a generally planar flange portion and a tubular connectorpiece on a first face, for connecting a suction tube to an aperturethrough the flange portion to the other face, said other face havingprojections defining flow channels facilitating flow of fluid towardssaid aperture.

[0015] Preferably, the suction head described above is combined with asurgical drape, the drape comprising a thin, flexible, adhesive-coatedplastic film, and the tubular connector piece extends through an openingin the plastic film with the adhesive coating adhered to said first faceof the flange portion.

[0016] Preferably, the suction head is used in conjunction with anopen-celled foam pad so that one surface of the foam pad is placed incontact with a wound area and the suction head applied to the othersurface of the foam pad. In the case of deep wounds the foam may beshaped and placed so that it is packed into the wound cavity asdescribed in our above-cited PCT applications. According to anothertechnique, which is particularly applicable to superficial wounds, thefoam pad may be a relatively thin pad which is placed over the wound.The suction head is placed in contact with the open face of the foam padand the drape applied over the suction head to fix the assembly to thepatient's skin.

[0017] Various types of open celled foams can be used as described inour above-cited PCT applications. The foam may be a polyurethane foambut polyvinyl acetate (PVA) foams are preferred, especially when used asa pad which placed over the wound. These are to some extent hydrophilic,which seems to exhibit beneficial comfort properties when applied to theskin. Wound healing is stimulated by maintenance of moist conditions inthe wound area, and this is facilitated by using a hydrophilic foam.

[0018] Finally, many other features, objects and advantages of thepresent invention will be apparent to those of ordinary skill in therelevant arts, especially in light of the foregoing discussions and thefollowing drawings, exemplary detailed description and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Although the scope of the present invention is much broader thanany particular embodiment, a detailed description of the preferredembodiment follows together with illustrative figures, wherein likereference numerals refer to like components, and wherein:

[0020]FIG. 1 represents a conventional design of surgical drape;

[0021]FIG. 2 represents a variation in the design of the handling barsat one end of the drape shown in FIG. 1;

[0022]FIG. 3 is a view similar to FIG. 1 of a surgical drape inaccordance with the invention;

[0023]FIG. 4 is a plan view of the surgical drape shown in FIG. 3;

[0024]FIG. 5 is a plan view from beneath of a suction head in accordancewith the invention;

[0025]FIG. 6 is a side elevation of the suction head shown in FIG. 5;

[0026]FIG. 7 is a view similar to FIG. 6 but shows the suction headsecured to a skin surface with the drape and with a foam pad locatedbetween the head and the skin surface;

[0027]FIG. 8 is a perspective view of the drape with a central stripportion of the protective sheet in the course of being removed; and

[0028]FIGS. 9a through 9 c illustrate the steps of affixing the dressingassembly to a wound area on a patient's leg and attachment to a negativepressure assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] Although those of ordinary skill in the art will readilyrecognize many alternative embodiments, especially in light of theillustrations provided herein, this detailed description is exemplary ofthe preferred embodiment of the present invention, the scope of which islimited only by the claims appended hereto.

[0030] Referring to FIGS. 1 and 2 of the accompanying drawings, aconventional laminate for use as a surgical drape comprises a thin,flexible, transparent film 1 which is adhesive-coated on one face 2,normally with a high-tack pressure-sensitive adhesive, and is protectedwith a releasable layer 3. The thin plastic film is conveniently ofpolyurethane because is transmits moisture. Layer 3 is normallyconsiderably thicker than film 1 and is coated on the surface adjacentto the adhesive with a releasable material such as a silicone tofacilitate stripping away from the adhesive-coated film.

[0031] In order to facilitate removal of the adhesive-coated film priorto use of the device, handling bars 4 are bonded at each end to theadhesive-coated film 1. Thus, by holding one of the bars 4, theprotective layer 3 can be stripped off and the adhesive face applied tothe skin of the patient. To facilitate handling of the thin, flexiblefilm 1, a strengthening plastic film 5 is frequently applied to the freeface of the plastic film 1. This is generally also transparent ortranslucent. Film 5 is preferably not bonded with adhesive to film 1,but may remain in contact by reason of electrostatic forces or becauseof close contact between the two conforming surfaces of film 1 and film5.

[0032] Usually, the surgeon or nurse will wish to strip off theprotective layer 5 after the film 1 has been correctly placed on thepatient's skin, and this can be facilitated by making partial cuts 6through the film 1 and 5, so that as the handling bar 4 is drawn upwardsfrom the patient's skin, the adhesive film 1 remains adhered to thepatient, while the patient, while the partial cuts 6 cause separation ofthe flexible film from the strengthening film 5. Strengthening bars 7may be provided to hold the lateral edges of the strengthening film 5and film 1 together with their main parts.

[0033] An alternative arrangement is shown in FIG. 2, in which thestrengthening film 5 is provided with a separate overlapping handlingbar 14, to facilitate its removal from the flexible film 1.

[0034] Further details of the make-up and manufacture of surgical drapesare given in U.S. Pat. No. 5,437,622 and European patent application no.0161865 and the prior art referred to therein, by this reference, thefull disclosure of U.S. Pat. No. 5,437,622 and European patentapplication no. 0161865 are incorporated herein as though each now setforth in its respective entirety.

[0035] Referring to FIGS. 3 and 4, the surgical drape of the presentinvention comprises a protective outer film 20, laminated to a thin,flexible film 21. The flexible film includes an adhesive-coated layerwhich is protected with a release-coated sheet material 24. Lateraledges of the flexible film 21 are provided with handling bars 23. Thusfar, the design is essentially the same as that shown in FIGS. 1 and 2.

[0036] The drape of the present invention differs from the drape shownin FIGS. 1 and 2 in that an aperture 25 is but through the strengtheninglayer 20 and through the flexible layer 21. The other differencecompared with the prior art drapes is that the protective releasablelayer is formed in at least two sections.

[0037] In the embodiments shown in FIGS. 3 and 4, the central portion ofthe releasable layer comprises a strip 26, having flaps 27 which overlapthe remaining outboard portions of the releasable layer. The purpose ofthis is to enable the central strip 26 to be removed first, withoutdisturbing the remaining portions of the releasable layer. The drape canthen be fitted around the wound area and, if desired, a suction deviceor other treatment device passed through the aperture 25 and secured tothe patient's skin with the peripheral areas of exposed adhesive coatedfilm.

[0038] An example of a device for applying suction to the wound area isillustrated in FIGS. 5, 6, and 7.

[0039] Referring to these figures, the suction head comprises a flangeportion 30 having a tapered edge 31, and a profile which may be of anydesired shape but is generally rounded at its edges. On the face of theflange 30 intended for contact with the patient's skin or a foam pad areformed a series of projections 32 which are distributed over the surfaceof the flange apart from the peripheral edge portion 31. The purpose ofthese projections is to provide fluid channels 33 facilitating the flowof fluids form any point of the flange to a central point 34, from whichit is intended to apply suction. The suction head includes a connector35, located above the aperture 34, having a tubular end 36 adapted forreceiving and connecting a catheter. The tubular and may have anoutwardly tapered portion to facilitate feeding a catheter into theconnector. The upper surface 37 of the suction head has a substantiallysmooth surface.

[0040] In use, the connector portion 35 is sized so that it extendsthrough the aperture 25 in the surgical drape shown in FIGS. 3 and 4,with the adhesive surface around the aperture bonded to the smoothsurface 37 of the flange 30. The suction head may be packaged in thiscondition with the surgical drape so that in use, the strip 26 isremoved by pulling on the handles 27 thus exposing the adhesive surfacein the vicinity of and surrounding the suction head. The suction headcan then be fixed in the desired position on the patient's wound andthen the remaining portion of the protective film removed to fix thedrape to the patient. The flange 30 of the suction head may be somewhatoval as shown in FIG. 5, and have dimensions as indicated in thisFigure, i.e. a longer dimension of about 95 mm and short dimension ofabout 70 mm. Alternatively, the flange may be circular and be smaller inplan view. For example, the diameter of a circular suction head may befrom about 30 to 50 mm in diameter, e.g. about 40 mm. It has been foundthat the suction head flange should not overlap the area of the wound.Thus, in the case of smaller wounds a smaller head is indicated.

[0041]FIG. 7 shows the suction head attached to a wound area 71 of apatient 70. The suction head is pressed into firm contact with aflexible, open-celled foam 73, which is itself pressed into contact witha wound area 71. The suction head and foam pad are pressed into contactwith the wound area by a surgical drape 20 having an adhesive surface74. The adhesive surface is bonded to the patient's skin outside theperiphery of the foam pad and suction head. It is also bonded to uppersurface 37 of the suction head. An aperture is formed in the drape topermit the connector portion 35 to extend upwardly through the drape. Inorder to avert the danger of incorrect catheter tubes being fitted tothe connector 35, the latter may have a customized cross-section orinternal projection such as a rib or key which cooperates with acorresponding slot, or key way in the catheter. Alternatively, thecatheter may be molded with a projection or longitudinal rib whichoperates with a corresponding slot or key way in the aperture of theconnector 35.

[0042] The foam pad may be packaged in a plastic pouch, sterilized bygamma irradiation and supplied in the same box or in other packing unitsas the suction head and drape.

[0043]FIGS. 8, 9a, and 9 b illustrate the way in which the drape-suctionhead combination is fitted to a wound on the patient's skin. In FIG. 8,a backing sheet 101 having a release coated surface is removed in thefirst step from the adhesive face 102 of the drape to expose the face ofconnector 30. A pad 103 of foam is positioned over the wound area andthe drape placed over the foam pad, the drape being adhered to the skinabove and below the pad (FIG. 9a). The lateral protective strips 104 and105 are removed in turn from the drape and the assembly adhered to theskin (FIGS. 9b and 9 c). Finally, spout 36 is connected to a tube 106which is then connected to a source of suction, e.g. a pump as describedin our above PCT application, in order to apply negative pressure to thewound. The suction head and drape assembly as shown in FIG. 8, with thesmooth surface 37 adhered to the drape, is conveniently packaged in aneasily openable plastic bag or pouch, and sterilized for immediate use.

[0044] While the foregoing description is exemplary of the preferredembodiment of the present invention, those of ordinary skill in therelevant arts will recognize the many variations, alterations,modifications, substitutions and the like as are readily possible,especially in light of this description, the accompanying drawings andclaims drawn thereto. In any case, because the scope of the presentinvention is much broader than any particular embodiment, the foregoingdetailed description should not be construed as a limitation of thescope of the present invention, which limited only by the claimsappended hereto.

What is claimed is:
 1. A wound therapy combination, comprising: asuction head comprised of a plurality of channels for facilitating flowof fluids to an opening of said suction head, wherein said opening isadapted for connection to a suction tube; and wherein said channels aredefined by a plurality of projections from said suction head, such thatsaid projections are in contact with a wound surface.
 2. The woundtherapy combination of claim 1, further comprising a surgical drapehaving an aperture coincident said opening, said surgical drapeextending over a region, and overlapping beyond the perimeter of saidsuction head, and wherein said surgical drape comprises a flexibleadhesive coated film adhered to said region of said suction head and arelease-coated backing extending over said suction head and adhered tothe overlapping portion of said surgical drape.
 3. The wound therapycombination of claim 2, further comprising a source of suction.
 4. Thewound therapy combination of claim 3, wherein said source of suction isa pump.
 5. A wound therapy device, comprising: a suction head having afirst face; a second face opposite said first face; an opening throughsaid first face and through said second face; and a plurality of flowchannels in fluid communication with said opening for facilitating flowof fluids to said opening.
 6. The wound therapy device of claim 5further comprising a surgical drape having an aperture coincident saidopening, said surgical drape extending over a region of said first face,and overlapping beyond the perimeter of said first face.
 7. The woundtherapy device of claim 6 wherein said surgical drape comprises aflexible adhesive coated film adhered to said region of said first faceand a release-coated backing extending over said second face and adheredto the overlapping portion of said surgical drape.
 8. The wound therapydevice of claim 7 further comprising a foam interposed between saidsecond face and a wound.
 9. The wound therapy device of claim 5 furthercomprising a source of suction in communication with said opening. 10.The wound therapy device of claim 9 wherein said source of suction is apump.
 11. The wound therapy device of claim 5 wherein said flow channelsare defined by a plurality of projections from said second face.